1. Field
The present disclosure relates generally to manufacturing and, in particular, to manufacturing parts for aircraft. Still more particularly, the present disclosure relates to a method and apparatus for forming elongate members for an aircraft.
2. Background
With an aircraft, hundreds of thousands of parts may be manufactured and assembled to form the aircraft. For example, a wing of an aircraft may be formed from a wing box that may be associated with the fuselage of the aircraft. The wing box may extend from the root of the wing to the tip of the wing. Skin panels may be attached to the wing box to form the aerodynamic surfaces of the wing.
These skin panels also may include structural reinforcements. These structural reinforcements may include, for example, without limitation, stringers that may extend from the root of the wing to the tip of the wing. These stringers may be arranged within the wing to provide a desired structural stability and integrity for the skin panels such that operational loads may be applied to the wing.
As another example, the fuselage of the aircraft may be comprised of a truss or frame that may be covered by skin panels. The skin panels of the fuselage may be reinforced through the use of structures such as stringers. These stringers may extend along the length of the fuselage and may also extend around the circumference of the fuselage.
Aircraft stringers may be formed from different types of materials. For example, a stringer may be formed from a metal such as aluminum, titanium, or some other suitable metal. When stringers are formed of metal, the stringers may be initially formed with a straight shape. If the structure to which the stringer may be attached has a curve, the stringer may be changed in shape to conform the shape of the structure. For example, the wing, the fuselage, or both the wing and the fuselage may have curved sections of skin panels on which stringers may be located. These stringers for curved structures may be shaped to conform to the shape of the wing or fuselage on which the stringers may be placed.
A stringer may be shaped by bending the stringer with a tool. The bend formed in the stringer may have a curvature that conforms to the portion of structure that also may have a corresponding curve. Bending a stringer to have a bent shape may be more complex and time-consuming than desired.
Currently, a stringer may be bent using a tool in the form of a press. A human operator may position the stringer on the press. The operator may then apply a force to the stringer that causes the stringer to bend. Thereafter, the operator may release the force applied by the press and remove the stringer from the press.
The operator may then measure the amount of displacement in the stringer with the bent shape as compared to the original shape of the stringer. This measurement may be made using a gauge or other suitable measurement device. The displacement of the stringer may be used to identify the bend of the stringer.
If the amount of bend of the stringer is not great enough, the operator may then reposition the stringer back onto the press to increase the bend in the stringer using the press. In the same manner, the operator may use the press to apply pressure to the stringer to increase the bend in the stringer.
This process may be repeated many times until the stringer has a desired bend. Removing and replacing the stringer from the press may be undesirable.
Further, with this process, the accuracy in bending the stringer may not be as great as desired. If the stringer is bent such that the curvature of the bend is greater than desired, the stringer may need to be reworked to reduce the bend. Reworking the stringer to reduce the curvature of the bend may take additional time that may be greater than desired. In some cases, the bend in the stringer may be such that the stringer cannot be reworked. As a result, the stringer may be discarded and a new stringer may be processed. Consequently, the output in manufacturing stringers may be slower and more costly than desired.
Inexperienced operators may take even longer periods of time to form a stringer than experienced operators. As a result, if experienced operators are unavailable, even fewer stringers may be manufactured than desired in a given period of time.
Therefore, it would be desirable to have a method and apparatus that takes into account at least some of the issues discussed above, as well as other possible issues.